Oxidative Stress Markers in Obsessive-Compulsive Disorder

Introduction Obsessive–compulsive disorder (OCD) is a chronic, prevalent, and highly impairing psychiatric illness. Although the pathophysiology of OCD remains unknown, pathways involved in oxidative stress (OS) have been implicated. However, the complete clinical picture has been rarely considered, and it remains unclear whether oxidative dysregulation is inherent to OCD pathophysiology, or whether it is a consequence of confounding factors such as age, body mass index (BMI) or smoking. Objectives In this work, we aim to assess oxidant and antioxidant markers and its clinical correlates in a well characterized sample of patients with OCD and controls, to test the hypothesis that altered OS markers are associated with OCD, rather than to illness-related behavioral changes or comorbidities. Methods 60 patients with OCD and 60 age and sex-matched control volunteers were recruited and assessed for sociodemographic and clinical variables using the Yale-Brown Obsessive-Compulsive Scale-II, the Beck Depression Inventory-II and the State-Trait Anxiety Inventory and Mini International Neuropsychiatric Interview. Three oxidant [8-hydroxy-2’-deoxyguanosine (8-OhdG), malondialdehyde, protein carbonyl] and three antioxidant [catalase, glutathione-peroxidase and superoxide dismutase (SOD)] markers were assessed in serum using Enzyme-Linked Immunosorbent Assay (ELISA). After comparing between groups, the association between OS markers and OCD characteristics, psychiatric medication and psychiatric comorbidities was assessed among patients with OCD. All analyses were adjusted for BMI, smoking and presence of physical comorbidities. Results The six OS markers were similar between patients with OCD and controls. Among patients with OCD, patients with more obsessive and depressive symptoms had lower concentrations of 8-OHdG, although this correlation may be sensitive to extreme values. Also, those who were on higher doses of antidepressants had lower concentrations of SOD. The remaining OS markers were not associated with OCD characteristics, psychiatric medication, or comorbidities. Conclusions Our results suggest that OS markers in blood do not seem to be a good biomarker of disease in symptomatic adult patients with OCD, and that OCD characteristics and comorbidities do not seem to have a clear impact on OS profile. Several factors contribute to the robustness of our findings, namely the sample size, the adjustment for confounding factors, and the assessment of a representative panel of OS markers using strict experimental methods. Future studies should always control for confounding factors when assessing OS markers and study OS profile in more specific samples, such as children or treatment-naïve patients. Disclosure of Interest None Declared

Introduction: Psychiatry has been diagnosing its pathologies through the evaluation of the symptoms reported by patients, relying on a few complementary exams to exclude organic causes.Studies about transcranial magnetic stimulation and electroencephalography (TMS-EEG) are bringing, from a clinical point of view, crucial information to characterize the different pathophysiological biomarkers of the psychiatric diseases, leading not only to the evolution of diagnosis, but also to an improved, more individualized treatment.Objectives: Characterizing the state of the art of TMS-EEG and its use in psychiatric diagnosis and treatments of different diseases.Methods: We undertook a narrative literature review by performing a search on PubMed for English-written articles from the last 10 years.The query used was "TMS-EEG"; "TMS-EEG" AND "Schizophrenia" OR "Major Depressive Disorder" OR "Bipolar Disorder".Results: Transcranial magnetic stimulation (TMS) is a safe and reliable method of non-invasive brain stimulation that allows for the local activation of cortical areas through electromagnetic induction.When combining this method with electroencephalography (EEG), it enables the underlying mechanisms of brain diseases.TMS is a powerful therapeutic technic in Major Depressive Disorder (MDD).The literature refers to an enhanced N45 and N100 amplitude, which indicates a baseline cortical inhibition that can indicate a depressed state, which can be used as a clinical biomarker to evaluate TMS treatments.In Schizophrenia (SCZ), TMS-EEG reveals a decreased cortical inhibition and excitation.Indices of inhibition and excitation reductions were also related to cognitive deficits.The current studies regarding Bipolar Disorder (BD) are not so consistent, revealing that there are shared neural pathways with MDD and SCZ.This is a pathology often misdiagnosed with MDD, so biomarkers would help to diagnose BD earlier and improve its prognostic.Conclusions: TMS-EEG can be used to provide more accurate neural targets, leading to more powerful and personalized interventions in psychiatric disorders, as well as more accurate diagnoses.As for future studies, it would be relevant to assess not only TMS treatment effects, but also pharmacological results in these different pathologies.

Disclosure of Interest: None Declared
Obsessive-Compulsive Disorder

EPV0638 Oxidative Stress Markers in Obsessive-Compulsive Disorder
A. Maia1,2,3 *, J. Oliveira 1,2 , N. Descalço 1,2,4 , B. Barahona-Corrêa 1,2 and A. J. Oliveira-Maia 1,2 Introduction: Obsessive-compulsive disorder (OCD) is a chronic, prevalent, and highly impairing psychiatric illness.Although the pathophysiology of OCD remains unknown, pathways involved in oxidative stress (OS) have been implicated.However, the complete clinical picture has been rarely considered, and it remains unclear whether oxidative dysregulation is inherent to OCD pathophysiology, or whether it is a consequence of confounding factors such as age, body mass index (BMI) or smoking.Objectives: In this work, we aim to assess oxidant and antioxidant markers and its clinical correlates in a well characterized sample of patients with OCD and controls, to test the hypothesis that altered OS markers are associated with OCD, rather than to illness-related behavioral changes or comorbidities.Methods: 60 patients with OCD and 60 age and sex-matched control volunteers were recruited and assessed for sociodemographic and clinical variables using the Yale-Brown Obsessive-Compulsive Scale-II, the Beck Depression Inventory-II and the State-Trait Anxiety Inventory and Mini International Neuropsychiatric Interview.Three oxidant [8-hydroxy-2'-deoxyguanosine (8-OhdG), malondialdehyde, protein carbonyl] and three antioxidant [catalase, glutathione-peroxidase and superoxide dismutase (SOD)] markers were assessed in serum using Enzyme-Linked Immunosorbent Assay (ELISA).After comparing between groups, the association between OS markers and OCD characteristics, psychiatric medication and psychiatric comorbidities was assessed among patients with OCD.All analyses were adjusted for BMI, smoking and presence of physical comorbidities.Results: The six OS markers were similar between patients with OCD and controls.Among patients with OCD, patients with more obsessive and depressive symptoms had lower concentrations of 8-OHdG, although this correlation may be sensitive to extreme values.Also, those who were on higher doses of antidepressants had lower concentrations of SOD.The remaining OS markers were not associated with OCD characteristics, psychiatric medication, or comorbidities.
Conclusions: Our results suggest that OS markers in blood do not seem to be a good biomarker of disease in symptomatic adult patients with OCD, and that OCD characteristics and comorbidities do not seem to have a clear impact on OS profile.Several factors contribute to the robustness of our findings, namely the sample size, the adjustment for confounding factors, and the assessment of a representative panel of OS markers using strict experimental methods.Future studies should always control for confounding factors when assessing OS markers and study OS profile in more specific samples, such as children or treatmentnaïve patients.

EPV0640
Professional Tennis Players and their subsceptibility for Obsessive-Compulsive and Depressive Symptoms

G. Cappellato
Introduction: A moderate sport activity is considered beneficial for both physical and mental health.On the contrary, different studies have shown that professional players may be more vulnerable to suffer from psychological and/or psychiatric disorders.
Objectives: Given the limited information available, the present study aimed to investigate the possible presence of depressive and obsessive-compulsive symptoms or disorders in a group of professional tennis players.Methods: Twenty-five current or former professional tennis players (18 men and 7 women; mean age AE SD: 42.32 AE 13.45 years), were recruited within the Italian Tennis Federation during an international competition and during a master meeting of coaches.They were compared with a control group, recruited from university students, doctors and nurses.All of them underwent a psychiatric interview with a structured scale and a psychopathological assessment carried out with the Mini-International Neuropsychiatric Interview (MINI), the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Self Assessment Scale for Depression (SAD).Results: The Y-BOCS total and subscale scores were significantly higher in both current and past athletes than controls.Current athletes showed higher scores at Y-BOCS total, subscales and some items.The majority of the current athletes also showed superstitions and magical thinking.Conclusions: The present study demonstrated that professional tennis players show a relevant increase of obsessive-compulsive symptoms and supertistions than controls.Interestingly, current athletes resulted more severe than past ones.Taken together, our findings support the notion that agonistic sport activities of high level require intensive training and compliance to strict daily routines that might represent a sort of vulnerability toward the onset of full-blown obsessive-compulsive disorder (as well as other disorders) in more fragile individuals.Not suprisingly, sport psychological support experts are increasingly needed.

EPV0641
Obsessive-compulsive disorder comorbid with rheumatoid arthritis: case report and review of literature H. S. Amani* and M. Rim Introduction: Obsessive-compulsive disorders are complex pathologies causing a major psychosocial handicap.However, their association with a disabling somatic pathology such as rheumatoid arthritis makes management more difficult.Objectives: To investigate through a case analysis and a review of literature the association between obsessive-compulsive disorder (OCD) and rheumatological disorders.Methods: We reported a case of a woman with a long history of obsessive compulsive disorder who presented rheumatoid arthritis and we conducted a review of literature through search on Pub-Med/MEDLINE following the terms "obsessive-compulsive disorder", "rheumatoid arthritis", "association", "inflammation".Results: Case presentation: A 62-years old woman who had been followed at the psychiatric consultation for 20 years for OCD.She had been stabilised on clomipramin at a dose of 100 mg per day until 2012 and since then she had been lost to follow-up with the notion of poor compliance with the treatment.She re-consulted in August 2022 for worsening psychiatric symptoms such as phobic obsessions with delusional beliefs, verification compulsions, sleep disorders and multiple somatic complaints including diffuse arthralgia and chronic arthritis evolving for 6 months.The patient was put on risperidone 2mg with anxiolytic without improvement.She was referred to the rheumatology consultation where the diagnosis of very active rheumatoid arthritis was retained, hence she was put on 20mg of prednisolone per day with methotrexate.The evolution was marked by the accentuation of obsessions and compulsions with the appearance of depressive elements, hence the introduction of fluoxetine 40 mg per day, the increase in the dose of risperidone to 4 mg with the anxiolytic with an improvement on the somatic and psychiatric symptoms.Conclusions: Literature had shown that patients with this OCD usually suffer from inflammatory or rheumatological comorbidities.This association could complicate the management of these patients.doi: 10.1192/j.eurpsy.2023.1960